This old hymn by William Young Fullerton, sung to the tune of Londonderry Air which we used to sing many years ago, suddenly came into my mind. The various verses explain that there are things the writer cannot tell – how God should set His heart on the son of man, how silently he suffered, how He will win the nations and all the lands will worship Him.
Having set four ‘I cannot tells’ Fullerton then writes the second half of each stanza with a confident proclamation ‘But this I know.’ He knows the Lord has been born of Mary when Bethlehem was His only home, he knows that God heals the broken-hearted and calms our lurking fears. ‘But this I know,’ he declares that all nations will see His glory and skies will fill with rapture. The last line triumphantly declares ‘At last the Saviour, the Saviour of the world is come.’